import java.util.concurrent.atomic.AtomicInteger;

/**
 * 1.CAS是什么？==》compareAndSet
 *      比较并交换
 */
public class CASDemo {
    public static void main(String[] args) {
        AtomicInteger atomicInteger = new AtomicInteger(5);
        System.out.println(atomicInteger.compareAndSet(5, 2019));
        System.out.println(atomicInteger.compareAndSet(5, 2019));
        atomicInteger.getAndIncrement();
        System.out.println(atomicInteger.get());

    }
}
